THERE’S a very old Japanese expression that warns, “The nail that stands up gets hammered down.”

That may be true, but there’s a slightly less-old Brooklyn adage that warns, “You can take that hammer and go – !”

Which explains how Anthony Bianchi – a proud son of Bensonhurst – became the first American to win elective office in Japan. The new city councilman did it by defying the very thing that makes Japan Japan: He spoke his mind and didn’t care what anyone thought.

“The Japanese have difficulty saying what they feel,” said Bianchi, who returned to Brooklyn Borough Hall last week for a sushi-and-cannoli celebration of his April election victory. “But I say what I feel, and they respect that. I guess they elected me to shake it up.”

But still, how does a guy from Brooklyn – where the winner of an argument is usually just the person who can talk the fastest and a “diplomat” is someone who signals before cutting across three lanes of traffic – adapt to the curt civility of Japanese politics?

Simple: He made it adapt to him.

Bianchi was just a humble (well, humble by Brooklyn standards) English teacher in Japan when he struck up a friendship with the mayor of Inuyama, a small, central Japanese city of 75,000.

That friendship led to a city contract to run an English-language program in the local schools, which led to battles with a sclerotic education bureaucracy (what, you think we’re the only city with a sclerotic bureaucracy?).

“In every battle, I ended up telling them, ‘Look, we’re going to do it my way and if you don’t like it, too bad.’ I think they found my honesty refreshing.”

It was one thing shaking up the bureaucracy, but getting elected as a gai-jin – the vaguely racist word for “foreigner” – is no small undertaking in Japan, especially given the local mores.

“It did take me a while to learn that when a Japanese person says, ‘That’s a very good idea and we’ll consider it,’ it actually means, ‘Fuhgedaboudit,’ ” Bianchi said.

After 15 years of living in the Land of the Rising Sun, Bianchi has a Japanese wife and speaks the language fluently (albeit with a noticeable Bensonhurst accent). Still, he misses his native land.

“All of Japan is like one really good ethnic neighborhood in New York,” he said. “Problem is, there’s no other ethnic neighborhood.”